1. Technical Field
The present invention relates to a recording apparatus that is provided with a recording head that performs recording on a recording target medium and is further provided with a driving mechanism that is capable of causing the recording head to move in a direction toward the recording target medium and away from the recording target medium. In the following description of this specification, the term “recording apparatus” according to an aspect of the present invention encompasses various kinds of apparatuses, devices, machines, equipment, and the like such as an ink-jet printer, a wire dot printer, a laser printer, a line printer, a copying machine, and a facsimile machine, though not limited thereto.
2. Related Art
As described in JP-A-2004-314591, a recording apparatus of related art is provided with a carriage, a platen, a guiding unit, a working unit, and a power transmission unit. The platen is an example of a recording target medium supporting unit. The guiding unit is an example of a carriage-supporting unit. The working unit and the power transmission unit make up an example of a driving mechanism. The carriage is provided with a recording head that performs recording such as printing on a sheet of printing paper. Printing paper is a non-limiting example of a recording target medium. The recording head is provided in such a manner that it can move together with the carriage in the direction of the width of a sheet of printing paper. The platen is provided opposite to the recording head so as to support a sheet of printing paper. The guiding unit supports the carriage in such a manner that the carriage can reciprocate in the paper-width direction as guided by the guiding unit. The working unit, which is, for example, a movement force application unit, is configured to move the guiding unit in a direction along which the recording head and the platen are provided opposite to each other. The power transmission unit can transmit driving power from a driving power source to the working unit.
Since a recording apparatus of the related art has a configuration explained above, it is possible to transmit power to the working unit through the driving operation of the driving power source. As the working unit applies a moving force to the guiding unit under the transmitted power, the guiding unit is moved in the direction along which the recording head and the platen face each other. As a result of such operation, a recording apparatus of the related art is capable of switching over the positions of a so-called platen gap, which is a distance between the recording head and the platen. The power transmission unit includes a plurality of gears. Because of such a configuration, so-called backlash, which is a gear tolerance, occurs when the driving power source is operated in a normal rotation direction or a reverse rotation direction. In an effort to provide a technical solution to a backlash problem, a sensor and a light-shielding plate are provided for measuring the position and the phase of the working unit. In such a related-art configuration, the sensor is an example of a detection device, whereas the light-shielding plate is an example of a detection target object. With the use of such a detection mechanism, a recording apparatus of the related art makes a judgment on the position and the phase of the working unit for the controlling thereof. Specifically, a recording apparatus of the related art is configured in such a manner that the sensor detects the light shielding plate in a “stable” area where a platen gap does not change even when the phase of the working unit changes. Having such a configuration, a recording apparatus of the related art is capable of controlling the position of the recording head and performing a platen-gap switchover with high precision.
However, a recording apparatus of the related art has a disadvantage in that its hardware configuration is less simplified because it requires for the sensing unit explained above. In addition, it is likely that, or at least there is an adverse possibility that, the production cost thereof increases because the sensing unit must be provided.